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The Pot Keyboard Integrated Circuit (POKEY) is a digital I/O chip found in the Atari 8-bit family of home computers and many arcade games in the 1980s. It was commonly used to sample (ADC) potentiometers (such as game paddles) and scan matrices of switches (such as a computer keyboard). POKEY is also well known for its sound effect and music generation capabilities, producing a distinctive square wave sound popular among chip tune aficionados. The LSI chip has 40 pins and is identified as CO12294.〔Michael Current, ("What are the SALLY, ANTIC, CTIA/GTIA, POKEY, and FREDDIE chips?" ), Atari 8-Bit Computers: Frequently Asked Questions〕 POKEY was designed by Atari employee Doug Neubauer, who also programmed the original ''Star Raiders''. Some of Atari's arcade systems use multi-core versions with 2 or 4 POKEY chips in a single package for more sound voices. The Atari 7800 allows a game cartridge to contain a POKEY, providing better sound than the system's audio chip. Only two games make use of this: the ports of ''Ballblazer'' and ''Commando''. The USPTO granted U.S. Patent 4,314,236 to Atari on February 2, 1982 for an "Apparatus for producing a plurality of audio sound effects". This referred to POKEY's sound generation abilities. The inventors listed were Steven T. Mayer and Ronald E. Milner. No longer manufactured, POKEY is now emulated in software by classic arcade emulators (e.g. MAME) and Atari 8-bit emulators. ==Features== * Audio * * 4 semi-independent audio channels * * Channels may be configured as one of: * * * Four 8-bit channels * * * Two 16-bit channels * * * One 16-bit channel and two 8-bit channels * * Per-channel volume, frequency, and waveform (square wave with variable duty cycle or pseudorandom noise) * * 15kHz or 64kHz frequency divider. * * Two channels may be driven at the CPU clock frequency. * * High-pass filter * Keyboard scan (up to 64 keys) + 2 modifier bits (Shift, Control) * Potentiometer ports (8 independent ports, each with 8-bit resolution) * High Resolution Timers (audio channels 1, 2, and 4 can be configured to cause timer interrupts when they cross zero) * Random number generator (8 bits of a 17-bit polynomial counter can be read) * Serial I/O port * Eight IRQ interrupts 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「POKEY」の詳細全文を読む スポンサード リンク
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